Ryania
Quick Facts
- Type
- Botanical Insecticide (No Longer Available)
- Source
- Ground stems and roots of Ryania speciosa, a shrub native to Trinidad and northern South America. The active compound is ryanodine, which binds to calcium release channels in muscle tissue.
- OMRI Listed
- No
- Bee Safe
- No — apply in evening
- Pet Safe
- Caution
- Residual
- 3–7 days
- Best For
- Historical use against codling moth in orchards. Ryania was considered gentler to beneficial insects than some alternatives because it acted primarily as a stomach poison (requiring ingestion) rather than a contact poison. No current recommended use.
What Is Ryania?
Ryanodine locks calcium release channels in the open position, causing continuous calcium flood into muscle cells. This produces sustained muscle contraction (tetany), paralysis, and death. The mechanism is unique among insecticides and affects both insect and vertebrate muscle tissue. Ryanodine receptors are highly conserved across animal species, which is both what makes ryania effective and what makes it dangerous to non-target organisms.
Source: Ground stems and roots of Ryania speciosa, a shrub native to Trinidad and northern South America. The active compound is ryanodine, which binds to calcium release channels in muscle tissue.
What Pests Does Ryania Kill?
Ryania is effective against the following pests:
How to Apply Ryania
Best for: Historical use against codling moth in orchards. Ryania was considered gentler to beneficial insects than some alternatives because it acted primarily as a stomach poison (requiring ingestion) rather than a contact poison. No current recommended use.
Avoid for: All current use. Product is not available and better alternatives exist. CpGV (codling moth granulovirus), kaolin clay, and Bt kurstaki provide effective codling moth control with dramatically better safety profiles.
Residual activity: 3–7 days
Safety Profile
| Category | Rating |
|---|---|
| Bee Safety | 🔴 Toxic to bees while wet |
| Pet Safety | 🔴 Use caution around pets |
| Overall Rating | Caution — Use with caution — timing and technique matter |
Why Isn't Ryania Working?
If Ryania isn't delivering results, check these common failure modes:
Product has been commercially unavailable since approximately 2000
Ryania speciosa is difficult to cultivate outside its native tropical range, making supply unreliable
Ryanodine affects vertebrate cardiac muscle — mammalian toxicity is significant
Variable alkaloid concentration in plant material made consistent dosing difficult